[19] The regiment fought at Leetown area of the battlefield during Pea Ridge on March 7–8, 1862, under the command of Colonel Evander McNair.

[21] The 4th Arkansas reconsolidated at Van Buren, Arkansas, then marched overland to Des Arc where the regiment was transported by steamboat to Memphis in an attempt to unite the Army of the West with the Confederate Army of Mississippi to attack Grant at Pittsburg Landing, Tennessee, but arrived too late for the Battle of Shiloh.

[24] All twelve-month regiments had to re-muster and enlist for two additional years or the duration of the war; a new election of officers was ordered; and men who were exempted from service by age or other reasons under the Conscription Act were allowed to take a discharge and go home.

[27][28] During the Kentucky Campaign, McNair's brigade was assigned to Churchill's division, under the overall command of General Kirby Smith.

[20] General Smith pushed rapidly into the bluegrass region of Kentucky, and defeated the Union army at the Battle of Richmond.

[20] On the same day, Henry Gaston Bunn was elected Colonel of the 4th Arkansas as the replacement for Brigadier General McNair.

[21] In accordance with Confederate Adjutant and Inspector General's Office Order Number 131,[30] nine soldiers of the regiment were recognized for courage and good conduct on the field for the Battle of Murfreesboro[31] In June, 1863, McNair's Brigade was reassigned to Walker's (later French's) Division of the Army of the Department of Mississippi and Eastern Louisiana, under the overall command of General Joseph E. Johnston who was assigned the mission of organizing a force to attempt to relieve General Pemberton's besieged army at Vicksburg.

[20][32] Johnston had been gathering troops at Jackson, intending to relieve pressure on Lt. Gen. John C. Pemberton's beleaguered garrison.

Johnston hastily withdrew his force across the Big Black River and Champion's Hill battlefields with Sherman in pursuit.

The heaviest fighting in the Siege of Jackson[34] came on July 11 during an unsuccessful Union attack, which resulted in heavy casualties.

[21] At the Battle of Chickamauga, McNair's was one of the eight brigades which, under Major General James Longstreet's direction, rushed through the gap in the Federal line and put one wing of the Union army to rout.

[21] Following the Battle of Chickamauga, NcNair's Brigade moved back to central Mississippi to oppose General Sherman's Meridian Campaign.

The Meridian campaign was a "dress rehearsal" for the style of war against infrastructure that Sherman, as well as some of these very troops, would later practice in Georgia.

To counter the threat, Confederate President Jefferson Davis ordered troops to the area from other localities, including McNair's Brigade.

[39][40] Through the summer and fall of 1864 the 4th Arkansas and the rest of their brigade, now under the command of Brigadier General Daniel Harris Reynolds, participated in the Atlanta Campaign through Georgia as a part of the force attempting to stop Sherman.

The unit is entitled to the following Campaign Participation Credits:[41] After the Battle of Nashville, Tennessee, the Arkansas regiments of Reynolds' Brigade marched via Bainbridge, Alabama, Tuscumbia, Iuka and Corinth to Tupelo, Mississippi, where they went into camp on January 10, 1865.

[45] After the surrender, the men were offered free rail transportation (where available) in the direction of their homes, by what was left of the Southern railway companies.

A large number of men were killed or seriously injured in a railroad accident at Flat Creek Bridge, Tennessee, on May 25, 1865.

The following is taken from the Hempstead county newspaper Washington Telegraph:[46] At an early hour last Wednesday, the Battalion of volunteers under command of Lt. Col McNair took up the line of march for Missouri.

aye, fling its fold to the kindred breeze, emblem of dread to tyrant hordes, of freedom of the seas!